George Johnstone Stoney, LdR's assistant, discovered the numerous knots in M101 during observations made in Apr and May 1851. Samuel Hunter made a remarkly accurate sketch of M101 in Apr 1861. The sketch included various knots, based on multiple observations. John Herschel estimated the position in the GC based on this sketch. Hermann Kobold measured an accurate position in 1898 for a knot he took as NGC 5453, but it was an uncatalogued knot about half-way to the nucleus.

400/500mm - 17.5" this low surface brightness HII region in M101 was barely distinguishable at 220x as a very low surface brightness enhancement superimposed on the background glow of a spiral arm 3.4' SW of center.

600/800mm - 24" (5/24/20): at 375x; between faint and fairly faint, small, round, low surface brightness patch. Similar or slightly more evident than NGC 5458, which is 2.4' ESE. Located 3.4' SW of center of M101.

Notes by Steve Gottlieb